1. Field of the Invention
The present invention relates to an apparatus for determining information concerning the point in which a trajectory of the supersonic projectile passes through a predetermined measurement plane.
2. The Prior Art
When a projectile travels through the atmosphere with a supersonic velocity, a conically-expanding pressure or shock wave is generated, with the projectile being at the apex of the shock wave.
It has been proposed to provide apparatus for determining the position at which the trajectory of the projectile passes through a plane, employing transducers or the like to detect such a shock wave generated by a supersonic projectile. One such proposal is described in U.S. Pat. No. 3,778,059 (Rohrbaugh).
Other target systems are disclosed in Swiss Patent Specification Ch-PS 589,835, granted May 15, 1977, to Walti, and German Utility Model DE-GM 77 26 275 of Walti, laid open Mar. 16, 1978. Other prior art systems are known, as well, but none provides comprehensive training in proper marksmanship. The prior art target arrangements provide only partial information to the marksman about the progress of his shooting. For example, the aforementioned prior art references provide systems which determine a location at which a projectile fired at a target passes relative to the target. U.S. Pat. No. 3,233,904 offers an automatic target apparatus having an impulse switch for detecting projectile hits on a target and initiating operation of a target mechanism which drops the target from a fully raised to a fully lowered position.